Expandable reverse shoulder trial

Abstract

Described herein is an expandable shoulder trial for a reverse shoulder system including a rotatably adjustable insert housed within a humeral cup. The insert has proximal and distal ends, the proximal end having a concave recess therein adapted to receive a glenosphere prosthesis. The distal end of the insert includes a shaft, the shaft having a helical groove disposed on at least a portion thereof. A distal end of the humeral cup is inserted in a humeral stem. The humeral cup has a proximal end including a recess therein, the recess defined by a circular wall. A guide pin protrudes from the circular wall and is adapted to engage the helical groove of the insert shaft. The proximal end of the insert may rotate along an axis toward the proximal end of the humeral cup and along the same axis away from the proximal end of the humeral cup.

The invention claimed is: 
     
       1. A reverse shoulder system comprising:
 at least one stem member having a shaft portion adapted to be received in a canal of a humeral bone of a patient; 
 a trial cup and a prosthesis cup each adapted to be coupled at a distal end thereof to the at least one stem member, the trial cup and prosthesis cup each having a proximal end surface including a recess therein; 
 a trial insert and a prosthesis insert each including a proximal end surface and a shaft portion having a distal end, the shaft portion of the trial insert and prosthesis insert each adapted to be received in the recess of the trial cup and prosthesis cup, respectively, 
 wherein a linear trial distance is measured between the proximal end surface of the trial cup and the proximal end surface of the trial insert when at least a portion of the trial insert is coupled to the trial cup and is linearly adjusted into a desired position during trialing, and 
 wherein a linear prosthesis distance is measured between the proximal end surface of the prosthesis cup and the proximal end surface of the prosthesis insert when the prosthesis insert is coupled to the prosthesis cup, and 
 wherein the linear trial distance is substantially the same as the linear prosthesis distance. 
 
     
     
       2. The reverse shoulder system of  claim 1 , wherein the at least one stem member is a broach. 
     
     
       3. The reverse shoulder system of  claim 1 , wherein the at least one stem member is a humeral implant. 
     
     
       4. The reverse shoulder system of  claim 1 , wherein the at least one stem member is a broach and a humeral implant. 
     
     
       5. The reverse shoulder system of  claim 1 , wherein the at least one stem member has a proximal end including an engagement member and the distal end portion of both the trial cup and prosthesis cup include an engagement member configured to engage to the engagement member of the at least one stem member in order to couple either the at least one stem member and trial cup or at least one stem member and prosthesis cup. 
     
     
       6. The reverse shoulder system of  claim 1 , wherein the recess of the trial cup is defined by a circular wall, the circular wall having a guide pin protruding from the circular wall into the recess, the guide pin adapted to engage a helical groove of the shaft portion of the trial insert, such that the proximal end surface of the trial insert may be linearly adjusted by rotating the trial insert in a first direction along a longitudinal axis of the trial cup toward the proximal end surface of the trial cup and in an opposite direction along the longitudinal axis of the trial cup away from the proximal end surface of the trial cup by the interaction of the guide pin and the groove. 
     
     
       7. The reverse shoulder system of  claim 1 , wherein the proximal end surface of both the trial insert and prosthesis insert have a concave recess portion. 
     
     
       8. The reverse shoulder system of  claim 1 , wherein dimensions of the prosthesis cup are substantially the same as dimensions of the trial cup such that the prosthesis cup and trial cup are substantially a same size. 
     
     
       9. The expandable shoulder trial of  claim 1 , wherein an outer face of the trial insert adjacent the proximal end surface thereof includes a plurality of attachment locations adapted to be engaged by an adjustment tool. 
     
     
       10. A reverse shoulder system comprising:
 at least one stem member having a shaft portion adapted to be received in a canal of a humeral bone of a patient; 
 a trial cup and a prosthesis cup each adapted to be coupled at a distal end thereof to the at least one stem member, the trial cup and prosthesis cup each having a proximal end surface including a recess therein, the recess termination at a distal end surface; 
 a trial insert and a prosthesis insert each including a proximal end surface and a shaft portion having a distal end, the shaft portion of the trial insert and prosthesis insert each adapted to be received in the recess of the trial cup and prosthesis cup, respectively, 
 wherein a linear trial distance is measured between the distal end surface of the recess of the trial cup and the proximal end surface of the trial insert when at least a portion of the trial insert is coupled to the trial cup and is linearly adjusted into a desired position during trialing, and 
 wherein a linear prosthesis distance is measured between the distal end surface of the recess of the prosthesis cup and the proximal end surface of the prosthesis insert when the prosthesis insert is coupled to the prosthesis cup, and 
 wherein the linear trial distance is substantially the same as the linear prosthesis distance. 
 
     
     
       11. The reverse shoulder system of  claim 10 , wherein the at least one stem member is a broach. 
     
     
       12. The reverse shoulder system of  claim 10 , wherein the at least one stem member is a humeral implant. 
     
     
       13. The reverse shoulder system of  claim 10 , wherein the at least one stem member is a broach and a humeral implant. 
     
     
       14. The reverse shoulder system of  claim 10 , wherein the at least one stem member has a proximal end including an engagement member and the distal end portion of both the trial cup and prosthesis cup include an engagement member configured to engage to the engagement member of the at least one stem member in order to couple either the at least one stem member and trial cup or at least one stem member and prosthesis cup. 
     
     
       15. The reverse shoulder system of  claim 10 , wherein the recess of the trial cup is defined by a circular wall, the circular wall having a guide pin protruding from the circular wall into the recess, the guide pin adapted to engage a helical groove of the shaft portion of the trial insert, such that the proximal end surface of the trial insert may be linearly adjusted by rotating the trial insert in a first direction along a longitudinal axis of the trial cup toward the proximal end surface of the trial cup and in an opposite direction along the longitudinal axis of the trial cup away from the proximal end surface of the trial cup by the interaction of the guide pin and the groove. 
     
     
       16. The reverse shoulder system of  claim 10 , wherein the proximal end surface of both the trial insert and prosthesis insert have a concave recess portion. 
     
     
       17. The reverse shoulder system of  claim 10 , wherein dimensions of the prosthesis cup are substantially the same as dimensions of the trial cup such that the prosthesis cup and trial cup are substantially a same size. 
     
     
       18. The expandable shoulder trial of  claim 10 , wherein an outer face of the trial insert adjacent the proximal end surface thereof includes a plurality of attachment locations adapted to be engaged by an adjustment tool. 
     
     
       19. A method of determining proper deltoid tension using a reverse shoulder system comprising:
 inserting a shaft portion of a stem member in a canal of a humeral bone of a patient; 
 coupling a cup member at a distal end thereof to the stem member, the cup member having a proximal end surface including a recess therein; 
 inserting at least a portion of a shaft portion of a trial insert into the recess of the cup member; 
 moving the shaft portion of the trial insert within the recess of the trial cup until proper deltoid tension is achieved; 
 measuring a linear trial distance between the proximal end surface of the cup member and a proximal end surface of the trial insert upon achieving proper deltoid tension; and 
 removing the trial insert from the cup member and inserting at least a portion of a shaft portion of a prosthesis insert into the recess of the cup member such that a linear prosthesis distance measured between the proximal end surface of the cup member and a proximal end surface of the prosthesis insert is substantially the same as the linear trial distance. 
 
     
     
       20. A method of determining proper deltoid tension using a reverse shoulder system comprising:
 inserting a shaft portion of a stem member in a canal of a humeral bone of a patient; 
 coupling a trial cup at a distal end thereof to the stem member, the trial cup having a proximal end surface including a recess therein; 
 inserting at least a portion of a shaft portion of a trial insert into the recess of the trial cup; 
 moving the shaft portion of the trial insert within the recess of the trial cup until proper deltoid tension is achieved; 
 measuring a linear trial distance between the proximal end surface of the trial cup and a proximal end surface of the trial insert upon achieving proper deltoid tension; 
 uncoupling the trial cup from the stem member and coupling a prosthesis cup to the stem member, the prosthesis cup having a proximal end surface including a recess therein; and 
 inserting at least a portion of a shaft portion of a prosthesis insert into the recess of the prosthesis cup such that a linear prosthesis distance measured between the proximal end surface of the prosthesis cup and a proximal end surface of the prosthesis insert is substantially the same as the linear trial distance.